Tunable open-access microcavities for on-chip cQED

TL;DR

This paper introduces tunable on-chip microcavities with high finesse and small mode volume, suitable for cavity QED experiments, demonstrating potential for scalable quantum light-matter interfaces.

Contribution

The development of buckled-dome microcavities with high finesse, tunability, and high single-atom cooperativity, advancing scalable quantum photonic devices.

Findings

Reflectance-limited finesse of 3500 achieved

Mode volumes as small as 35λ^3 demonstrated

Single-atom cooperativity up to C1=65 reported

Abstract

We report on the development of on-chip microcavities and show their potential as a platform for cavity quantum electrodynamics experiments. Microcavity arrays were formed by the controlled buckling of SiO2/Ta2O5 Bragg mirrors, and exhibit a reflectance-limited finesse of 3500 and mode volumes as small as 35lambda^3. We show that the cavity resonance can be thermally tuned into alignment with the D2 transition of 87Rb, and outline two methods for providing atom access to the cavity. Owing to their small mode volume and high finesse, these cavities exhibit single-atom cooperativities as high as C1 = 65. A unique feature of the buckled-dome architecture is that the strong-coupling parameter g0/kappa is nearly independent of the cavity size. Furthermore, strong coupling should be achievable with only modest improvements in mirror reflectance, suggesting that these monolithic devices could provide a robust and scalable solution to the engineering of light-matter interfaces.